Takedown mechanism for firearms



Sept. 16, 1952 D. EMERSON TAKEDOWN MECHANISM FOR FIREARMS 2 SHEETS-SHEET 1 Filed Feb. 16, 1949 Quad 5mm D. EMERSON 2,610,426

Sept. 16, 1952 TAKEDOWN MECHANISM FOR FIREARMS 2 SPEETS-SHEE'I 2 Filed Feb. 16, 1949 Patented Sepi. 16, 1952 TAKEDOWN MECHANISM FOR FIREARMS David Emerson, New Haven, Conn., assignor to 01in Industries, Inc., New Haven, Conn., a corporation of Delaware Application February 16, 1949, Serial No. 76,681

9 Claims. (01. 42-75) The present invention relates in general to firearms and more especially to a firearm of the takedown type, that is to say, a firearm in which the barrel-unit and frame-unit of the firearm are readily separable one from the other, for convenience in packing, shipping and carrying. T

An object of the invention is to provide a firearm with superior takedown-means for readily attaching the barrel-unit to the frame-unitof the firearm and'for detaching the barrel-unit,

from the frame-unit.- i

flAfurther object of the invention is to provide a takedown firearm with superior takedownmeans of durable and dependable construction and of relative simplicity and economy of manufacture. i v

A .still furtherobject of the invention is to provide a superior takedown-means for firearms embodying an improved detent for releasably locking the takedown-means against inadvertent release.

With the above and other objects in view, as will appear to those skilled in the art from the present disclosure, this. invention includes all features in the said disclosure which are novel over the prior art and which are not claimed in any separate application. I

In the accompanying. drawings, in whichcertain modes of carrying out the present invention are shown for illustrative purposes:'

Fig. 1 is a broken side elevation of a'firearm embodying. the improved takedown mechanism of this invention;

Fig. 2 is an enlarged broken side elevation of aportion of the firearm shown in Fig. 1, the fore-end being shown in section to illustrate the principal elements of the improved takedown mechanism;-

. Fig. 3 is a further enlargement of a fragmentary portion of the firearm shown in Fig. 2, the enlargement being a side elevation in section of the foreend and fra mentary sectional elevations of the barrel-locking lug and the forward end of the tubular magazine;

Fig. 4 is an endelevation in section of the fore-end and tubular magazine on line i4 of Fig. 3; Z

Fig. 5 is a perspective-view'of the connectorbolt of the takedown mechanism;

I Fig. 6 is an enlarged perspective view of the endplug of the tubular magazine showing the guide-recess in the front face thereof for accommodating theimproved guillotine detent; and

' I Fig: 7' isap'erspective view of the guillotine detent of the improved takedown mechanism of this invention.

v The particular takedown firearm herein chosen for illustrating the invention may be considered to include two principal units separable one from the other to enable the firearms to be more conveniently packed, shipped Clr carried. The one unit of the firearm may, for convenience of description, be designated as the frame-unit and comprises, in the main, the receiver H] having a buttstock ll secured at the rear end thereof and a tubular magazine I! secured to the forward end thereof, the tubular magazine I2 being in communication at its rear end with the breech-bolt chamber of the receiver.

The complementary barrel-unit comprises, in the main, a barrel [3 adaptedto be detachably secured in any suitable manner, such as by means of continuous or interrupted threaded engagement, within anaperture in the front face of the receiver; and a barrel-locking lug M. The latter is a substantially L-shaped member having a long leg-portion l5 fixedly secured to the underside of the barrel [3 longitudinally thereof and substantially intermediate its opposite .ends; and an apertured short leg l6 extending at substantially right angles to the long leg E5 of the locking-lug and projecting downwardly from the underside of the barrel, for the purpose hereinafter described, the aperture of the short leg l6 opening upon the front and rear faces of the short leg is and being provided with internal threads 11.

As shown in Figs. 3 and 4, the fore-end l8 of the firearm is provided. with a relatively-deep vertical recess l9 intersecting the topside there- 7 of and'eXtending from the rear end thereof forwardly throughout a major portion of its length, the recess I9 being substantially U-shaped in cross section and having a transverse dimension correspondin substantially to the diameter of the tubular magazine [2 for accommodating the latter. The forward end of the recess H9 intersects a relatively-shallow clearance-aperture 29 which also intersectsthe top side of the fore-end and is adapted to provide clearance for the short leg 16 of the barrel-locking lug 14 when the fore-end is assembled on the barrel-unit. The front wall of the aforesaid clearance-aperture 23' of the fore-end is intersected by the reare'nd of a counterbore 2| concentric to a longitudinal aperture 22 which extends forwardly through the fore-end to the front end thereof for accommodating the connector-bolt of the takedown mechanism, the forward end of the aforesaid aperture 22 and the front end of the fore-end being reinforced'by a grommet 23.

Referring again to the tubular magazine l2 of the firearm, the forward end of the tubular magazine is provided with a magazine-plug 24 which, as shown in Fig. 6 is a substantiallycylindrical member adapted to be secured in the forwardendofthe tubular magazine I2 by a transverse pin 25' which extends through a transverse aperture 26 of the plug and is engaged at 2,610,426 5.1T l t a its opposite'ends in axially-aligned apertures in the forward end of the tubular magazine. As.

shown in Fig. 4, the pin is provided With'an annular groove 21 intermediate :itscppositeends and extending substantially transversely of .its longitudinal axis.

The front end of the magazine-plug.isiormed with a U-shaped guide-recess 28, the upperend of which opens upon the top side or facefof the plug. Further, the guide-recess 28 lies in a vertical plane substantially parallel to but spaced rearwardly of the front face of the magazinelplug thereby to providethe guide-recess 28,.with aE'front wall .29, .the latter .beingecharacterized by a vertical substantially u-sshaped slot 30 which :also opens upon the topside ofthe plug, whereby the'front wall .29 of 'the'guideerecess constitutes, inefiect, 1a substantially u-shapedflange 3| extending '"inwardly from. 17116.;001'16S1JOBding substantially verticalaside walls 32-32 and the curved bottom wall 133 :of; the guide-recess.

The back wall 34 of the guide-recess comprises a substantially planar surface in spaced-parallel relationship .to its front Wall .29 land provided with an aperture 35 in the verticalplaneof but slightly above the longitudinal axis of the plug and terminating in'a. blind end 31 .immediately forwardly-of the rearlend of the plug. As shown in Figs. 3, 4 and 6, ':the :bottom wall of the hole 235 intersects the :top :wall of the plugaperture :26 substantially intermediate its oppossite ends such that when the magazine-plug is secured in the forward 'endof the tubular magazine by the pin 25, the annular groove 21 of the latter will be opposite :the intersection of the bot-- tom wall of the hole 35 with the top wall of'the transverse aperture 26. Further, it will be noted that the longitudinal axis of the drilled hole 35 is substantially in alignment both with the iongitu-dinal axis of the internally-threaded aperture if! "of the barrelelug and the longitudinal axis of the aperture '22, extending forwardly through the fore-end.

Referring again to Fig. 6, formed at the :lowest point in the bottom wall 330i the guide-recess 28 and coextensive with the vertical axis thereof, is

an aperture 38 constituting a well for accommodating. a coil-spring 39 which is adapted to sup- ,port the guillotine detent of the takedown mechanism in the guide-recess 28 of the magae zine-plug. Referring especially to Fig. 7, the guillotine detent, indicatedgenerally at, comprises a substantially rectangular plate approximately equal in thickness to the distance 'betw en the. flanged front wall 229 and the rear wall 34 of the guide-recess, whereby the guillotine detent is adapted to be-slidablyheld therein for substantially vertical-movement only, the detent being guided for vertical movement in the guide-, recess 28 by en a ement of the sides 4|? of the detent with the respective side walls 32-,-32 of the guideerecess. The upper edge 42 of, the

' uil t edete i c r ed as hown in Fi 4.,to.

qrresnond to the cu va ure of the up er urf e i th maeeein nlue and the inner wall pf the tubular magazine, the upper edge 42 of the guil lotine detent constituting stop-means adapted to engage squarely against the inner wall of the tubular magazine to limit the upward movement of the guillotine detent i'nthe guide-recess of the magazine-plug. The bottom edge 43 of the guillotine detent is curved to correspond to the curvature of the'xbottom wall 3,3 'of the guide-recess and is intersected 'atisubstantially the centerv of its arc of curvature by a rectangular slot 44 -extending upwardly from the bottom of the detent. When the guillotine detent is assembled V in the guideere'cess'of the magazine-plug, its rec hereinafter'idescribed.

. tangular. slot. is located immediately above the spring 3!! in the spring-retaining aperture 38 of themagazine-plug such that the upper end of thespring 39 adapted to abut against the upper edge '45 of the slot 44, thereby to resiliently support-and urge the guillotine detent upwardly in the guide-recess of the magazine-plug.

Formed at substantially the geometric center of theguillotine detent is agenerallymectangul-arly Shaped aperture 46, the .ouer-all dimensions of which are such ithfitithe connector-bolt of the takedown mechanism may pass: freely there:

through. as shown in Fig. .4. The bottom 41 of the aperture 46 is provided with aplurality f I upward y pr jectin :teeth :48 which are .intermediate its opposite ends and which extend transversely of the -;-bottom edge i4! :of theiaperture, that is to say, 'in the direction of the. lore gitudinal axis of the magazineeplugdor dockingly en a g the ,connecton-rod .Lof athe" gtak'eidown mechanism in adjust jd position; in :the manner The connector-rod of-theltakedow-n mechanism is indicated generally at 49 and, as shown "in F 5, comprises an elongated cylindrical bar having an enlarged, 'ecylindrica'l' head .50 at its forward end provided with a slot 511' in its front, face for receiving a toolor coin ifor turning the connector-rod; and an aperture 52 extending transversely. through the side of :thexcylindrical head for accommodating a wire nail or similar instrument when greater leverage-is required 101' turning the connectorerod. V

The opposite end "of the .co'nne'ctl'ir-r'od is "of reduced diameter and is provided with a beveled edge vas indicated at '53,: so that when-assembling the'rod in the longitudinal aperture of the fore-'- end and. the .saxia'llyealigned. vaperture of the magazine-plug, a's .hereinaiter 1 described; the beveled edge :53 oi the rod :willcamniingly :n'gage against the toothed edge of the-resiliently suppor-ted guillotine detent and displace the; latter downwardly in its guide-recess cf the magazineplug against 'the'resistance of the spring 39, thereby to enable the rear end of the connector-'rod'to pass through the aperture of the'gui llotine detent into the longitudinal aperture of the magazineplug. In this connection, the reduc'd diameter of the rear end cf the rea :cr s ch'size "that the latter is adapted tc-fit nicely in thg" aperture of the magazine-plugio firmly suppbrt the f;orward end of the tubularmagazine; and-to engage in the annular groove 2 1 of the fastening-pin -25 to lock the iatter against movement-in the trans-- verse aperture of the magazine-plug. Immediately forwardly er the beveled "end "of the rod; the periphery of-the 'latterY-is Zfi-utd in a manner to provide a plurality f spaced-parallel teeth :54 .extend-ingiongitudinally er the Fred, the dimensions and shape of the longitudinal teeth 54 corresponding substantially-to the te'etl l '61" thQi -uillotine 'detent so asito'meshi readily therewith as the connector-rod is pushed through the aperture of the guillotine detent, in the manner hereinabove described.

To insure engagement of the teeth 54 of the connector-rod with the teeth 48 of the guillotine detent, the teeth of the rodare elongated sufficiently normallyrto extend an appreciable distance on opposite sides respectively of the detent.

The connector-rod 49 forwardly of the elongated teeth 54, is formed with external screw threads 55 adapted to threadedly engage in the internally-threaded aperture ll ofthe short leg I6 of the barrel-lug, the threaded portion 55 of the rod extending normally an appreciable distance on opposite sides respectively of the short leg l5. Formed on the rod between the forward end of its externally-threaded portion 55 andits smooth shank-portion 56, is an annular groove 51 adapted to accommodate a snap-ring 58, the outside diameter of which is greater than the inside diameter of the longitudinal aperture 22 of the fore-end so that when the connector-rod is disconnected from the barrel-lug and the foreend removed from the underside of the barrel, the connector-rod will be held from dropping out of the fore-end. That is to say, the connectorrod is adapted to be assembled in the fore-end preparatory to assembling the fore-end on the barrel-unit by pushing the rod, reduced end first, through the longitudinal aperture thereof and then engaging the snap-ring 58 in the annular groove 51 to retain the connector-rod in the fore-end.

The assembly and operation of the elements of the improved takedown mechanism may be described briefly asfollows. The guillotine detent 40 and its spring 39 are first assembled in the guide-recess 28 of the magazine-plug 24, whereupon the latter is inserted in the forward end of the tubular magazine and secured therein by means of the transverse pin 25. The fore-end l8, including the connector-rod 49 assembled therein as hereinabove described, is then mounted on the underside of the barrel to enclose the tubular magazine, the-reduced rear end of the connectorrod being thrust through the internally-threaded aperture ll of the short leg l6 of the barrel-lug and the aperture 46 of the guillotine detent into the longitudinal aperture 35 of the magazineplug. The externally-threaded portion 55 of the connector-rod is then threadedly engaged in the aperture ll of the barrel-lug by applying a coin or other tool in the kerfed head of the connectorrod and rotating the rod in a clockwise direction. Continued rotation of the connector-rod will thereupon advance the longitudinal teeth 54 of the rod into engagement with the teeth 48 of the guillotine detent. Since the latter is resiliently mounted for vertical sliding movement only in the guide-recess of the magazine-plug, the camming' action effected by rotational engagement of the longitudinal teeth of the connector-rod with the teeth of the detent displaces the detent downwardly positively against the resistance .of its spring, the force of which moves the detent upwardly again as each longitudinal tooth of the rod wipes over a tooth of the detent. Thus, as the connector-rod is threaded into the barrel-lug,

the guillotine detent undergoes a short-stroke reciprocating movement-in the guide-recess of the magazine-plug. It will be appreciated also that as the connector-rod is threaded into the barrel-lug, engagement of the head of the connector-rod with the grommet 23 in the front face of the fore-end draws the fore-end I8 rearwardly relative to the barrel-unit so that the rear end of the fore-end is seated firmly against the forward end ofthe receiver. Additional rotation of the connector-rod thereupon tends to pull the barrel-unit forwardly relative to the frame-unit, the effect being to take up any backlash in the threaded connection of the' barrel with the receiver.

Once the fore-end and barrel have been pulled up tightly in assembled relationship on the receiver, the connector-rod is eifectively held from inadvertent rotation in a direction to loosen the fore-end and barrel by resilient engagement of the teeth 48 of the guillotine detent with the teeth 5d of the connector-rod, disengagement of which may be effected only by overcoming the resistance of the detent-spring.

ments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equiva lency range of the appended claims are intended to be embraced therein.

I claim:

1. In a takedown firearm, including in combination: a barrel-unit; a frame-unit including a tubular magazine; a fore-end constructed and arranged to be assembled on the underside of 7 said barrel-unit and said tubular magazine; and takedown mechanism for securing said fore-end and barrel-unit to said frame-unit and for preventing any relative movement between such parts, said takedown mechanism comprising conhector-means mounted in said fore-end and arranged to be threaded into said barrel-unit, and detent-means carried by said tubular magazine and arranged to engage said connector-means to hold the latter in threaded engagement with said barrel-unit.

2. A takedown firearm as defined in claim 1, which further includes resilient-means associated with said detent-means for normally urging said detent-means into engagement with said connector-means thereby to releasably hold the latter in threaded engagement with saidbarrelum 3. In a takedown firearm, including in combination: a barrel-unit; a frame-unit including a tubular magazine; a fore-end constructed and arranged to be assembled on the underside of said barrel-unit and said tubular magazine; and takedown mechanism for securing said fore-end and barrel-unit to said frame-unit and for preventing any relative movement between such parts, said takedown mechanism comprising connector-means having teeth thereon, said con hector-means being mounted in said fore-end and arranged to be threaded into said barrelunit, and detent-means carried by said tubular magazine, said detent-means having teeth arranged to engage the teeth of said connectormeans thereby to lock the latter in threaded engagement with said barrel-unit.

4. A takedown firearm as defined in claim 3, which further includes resilient-means associfagemaae nation: a barrel-unit; a frame-unit inemding "a tubular magazine ha-vin'gan end fi1ug; a f ore- "end;-constructed andafiranged to be assembled on the underside ofsaid 1oar-i el' iii'iit ami said tubu Tar magazine; andtakedown m'eehanism qfor seeuri-ng said fore-end and barrel-unit to said frame-unit and *fori preven ting any :relative movement b'etween parts, said -takeddWh mechanism "comprising connector :means moaiit ed in said fore-end andaeran'ged to be threaded into "Said barrl uriit, detentmreans, :rn'eans to 'slidably support said detent means inthe endp1u'g of said tubular magazine, and -'resi1ientmeans mountedin the end-plug (if said tu'bt'flar magazine, said resilient-means b'eing arranged normally to urge and resilieritly hold said detent-means in engagement with said eonnec'tormeans thereby to releasabiy hold the Iatter in threaded engagement with said b'arr'hunit.

6. 'In a takedown firearm, indiudihg' in c'ombi nation: a barrel-"unit; a "-frame-unit indlu ng --a tubular magazine having an end-plug prov ed with an aperture; a fore-end constructed and arranged to 'be assembled on the underside of said "barrel-whit and said tiibiilar magazine; and takedoWn mechanism for -securing said fore-end and barrel-unit to said frame-uriit-and for-preventing any relative movement between such parts, said-takedown:meehanismficomprising coni' hector-means mounted in said {Tore-end, -said connector-means being arrangedtoengagein the aperture of said end-plug and *to he threaded into said 'barrleuni t, ee'tene-means carried by said tubular magazine, said'deterrt-means having an aperture therethrough to receive said conhector-means, and resilient-means associated with said detentmreans for normally urging *said *detent-means into engagement with said 'co'nnectar-means thereby to -re1easaI-b1y =ho1d the-lat ter in threaded I engagement Withs'aidbarrelnnit.

'7. in a 'takedo'wn firearm, Einoludingimearribination: a barrel-unit; a frame-unit including a tubular magazine having an end-plug provic 'ied with a gu-ide reces's; a fore-end con'strueted and arranged 'to be assembled on the underside of said barrel uni't and eaid tu biilar' agaz'i'n'e; and ita'k'edo'wn mechanism for Scflri-h'g said ore-end and barrel-unit to said frame unit, {said ta-ke- -down mechanism comprising 'con-nec'tor means mounted in said fore-end and arranged tof be threaded into said barrel-unit, deten't means slidably mounted in the guide-recess of the endiplug 'of said tubular magazine, and resilient;

means mounted inthguid'e-Tlacess of said *enda ping, said resilient-means being arranged no'r mally to urge and resiliently hold said *d'etene means in renga'gementwith said conneetor ineans thereby to 'x elea'sa'bly hold the'iatter in threaded engagement with said -b'arrel uni't.

' 8. In a takedown firearm, including innom'b'ination: -a 'barrel -u'nit; 1a drama-unit inluding a bination: "a barr'el unit"; a frame fin it 8 tdbuiar :magazine :having an rendlug iprovided With aguide-recess in the face thereof; a Eforeend constructed and arrangedrtoebe"assembled on the underside of said"barre1-unit;and1?said tubular magazine; takedown mechanism for=se- "owning said fore end; and Ebar'r eI- nnit' toiasaid -fi ame-iunit, :'said :takedown mechanism comprise ingrconn'eetor-means having teeth thereon, :rsaid "conhecto'rmeans "being moiintedzinsaid sfioreend and arranged to Joe threaded into said barrernnit, detentmeans :sii-dably mounted Ions-uh;- stanti'aliy vertical movement'zoniy "the guide:- recesszin l the Iiir'ont face of sa'id *endf plug, maid deten-t m'eans vhaving teeth Ear-ranged Ito "engage the' teeth of said connector-means; :a'nd aidetentspiing mounted in the fguide reoess ':of said end- 'plug, said det'ent-spring :being arranged to 5m:- gagie fthe underside of said :deterfit -lmean's T1110?- 'mally to re'si lientiy hold the 'teeth of said :demivmeansin engagemem' witn the teeth mi saidcon neetor means" thereby "to relea sably mold the lat-- ter i-n threade'd engagement with :said Barrel"- unit. I

'ncmai n' ebralitd iil'g "a tuhular -magazi'ne having-an end-'plng proii ea With *a guide-recess in i-ts 'front' face anwan ap'e'rtl l-re :exten rig Substantially at right angles thereto; a foreend eonstmeteaandarran' be assembied ontnef findei'side-b'f SQiHbaHF flit a'inl'd s'aid tubfil'ar magazine; and talke jdfiwn m Iranism for securing said fore-end and' barre -unit to said frame-unit, said takedown mechanism com-prising a connector-rod having teem-thereon "and external threads, said {connects I rod being mounted in Sammie-611aand-arr ngejdto -em gage in the aperture of said end-"plug and to be threaded into said b alrl -unit, det'ent means s'lidably mounted for s1ibstantiai 1y-'vertiea 1move '-ment-'on1y in theguide rejcess {of 'sai'd end-pllig, said 'det'ent-means having an aperture centrally thereof to reeeive *s'aid connector-rod, and "teeth on one edge 'o'f s'aid aperture to'engagethe teeth of {said c'onn'eotor-rod, and fa detentrsprin'g mounted in the bottom-oi said guid'ereoes'sjs'aic'i detent-spring being arranged :engage the deraide r sai detent-means normally to resii ientl yhold the teeth 'offflsaid d'etentmea'n's m -em 'gagem'ent with the teeth of said enne-cto'r-roa thereby fto releasably old "the latter in threaded engagement-withsaidbarri u ih j V 'DAVIDEMERSON.

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